Are your email attachments being received as winmail.dat files?


Here is the solution to stop your email attachments being received as winmail.dat files, when using 365 – as a mail client.

There are 2 things to check

Check 1 – If ALL or MOST recipients are receiving attachments as winmail.dat files then make sure is set to send emails in HTML or Plain text formats…. NOT RTF as a default by doing the following.

      1. Open
      2. Click the File tab, click Options, and then click Mail.
      3. In the Compose Messages section, change “Compose messages in this format” to HTML
        office 365 Outlook default email set. Winmail.dat
      4. Scroll down to the Message Format section
        Check  “When sending messages in Rich Text Format to Internet recipients” is set to “Convert to HTML format
        convert files to HTML to eliminate winmail.dat
      5. Click the OK button to save the changes.

Check 2 – Having set the defaults to HTML and ALL or MOST recipients are still receiving attachments as winmail.dat files then you need to delete one or more suggested recipients in the List.

stores the last email format in the “” list. Either remove one or all of the complete list as follows:

            1. To remove one of the entries in the Recent People list, hover your mouse over the entry, you’ll see an X to the right of the person’s entry.
              remove-auto-complete-entry winmail.dat
              Click that X to delete the person’s name and email address from the List. This doesn’t remove the person from your Contacts folder or other address book.Now type the recipients address in full, do not choose from the suggested list.
            2. To remove the complete list
              1. Select File > Options > Mail.
              2. Under Send messages, choose Empty List.Choose File, Options, Mail, and under Send messages, choose the Empty Auto-Complete List button.
              3. Choose Yes to confirm you want to empty the list.

              4. Remove and empty the entire List as follows:

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